1. Field of the Invention
The invention relates to a network security device, and more particularly to a bypass circuit integrated in a single chip.
2. Description of the Related Art
Generally, a network security apparatus is applied between two or more networks, such as between Intranet and Internet. An application process of the network security apparatus can analyze network packages or signals passing therethrough to determine whether Internet safety risks exist in the networks. After the analysis, the network packages or signals are then transmitted by predetermined routes. When the network security apparatus fails, such as when the power supply is interrupted or when the system crashes, the networks connected to the network security apparatus will not communicate with each other. At this time, if the networks are requested to be remaining a state of communication, a bypass circuit is required.
Through a specific trigger state (an interruption of the power supply or a system crash), the bypass circuit allows two networks to be directly connected to each other in physical connection form without suffering the security application process of the network security apparatus. Thus, if there is a bypass circuit, when the network security apparatus fails, the networks connected to the network security apparatus can still communicate with each other. At this time, the network security apparatus does not perform the security application process to the network packages or signals any more.
Using a conventional network security apparatus each of whose network connectors has eight pins as an example, a bypass circuit for a pair of network connectors is composed of nine relays. The hardware lines between the nine relays occupy space and require greater complexity in circuitry design. Moreover, instantaneous current is generated when the relays are larger. The conventional network security apparatus does not conform to the tendency toward smaller size and low power consumption in circuitry design.